The present invention relates in general to liquid, semi-liquid and gelled extreme pressure functional compositions which contain an aminocarboxylic acid-terminated polyoxyalkylene.
Aminocarboxylic acid-terminated polyoxyalkylenes having three of fewer oxyalkylene units are known in the art. Known aminocarboxylic acid-terminated polyoxyalkylene compounds include ethylenebis(oxyethylenenitrilo) tetra acetic acid and ethylenebis(oxyethyleneimino) dimalonic acid. Known applications for these compounds include use as chelating agents and use in medical diagnostic tests.
Extreme pressure functional compositions are materials such as cutting fluids, lubricating oils, greases, and functional fluids such as coolants, hydraulic fluids, transmission fluids and brake fluids, which are used under conditions of extreme pressure. Although these compositions may perform additional functions, they are at least partly employed to reduce friction between moving parts in the system in which they are used. Therefore, maintenance of lubricating properties under extreme pressure is important.
The use of diamine compounds in functional compositions, such as cutting fluids, is known in the art. U.S. Pat. No. 4,043,925 to Felton, Jr. discloses a water based liquid for use in cold-forming metal parts which is a solution of a polyalkylene glycol, an extreme pressure additive, an anti-corrosion agent and a defoamer. The extreme pressure additive is a sulfochlorinated fatty acid. An alpha, omega diamine-terminated polyoxyalkylene is disclosed as a possible corrosion inhibitor. Similar diamines are also disclosed by U.S. Pat. No. 3,186,946 to Sluhan and U.S. Pat. No. 2,917,160 to Turinsky. Amino-terminated tertiary polyoxypropylenes are also known as lubricant additives. Other somewhat similar amines are disclosed by U.S. Pat. No. 4,185,485 to Schick et al.
Although these amines have many uses, fluids based on these amines frequently do not perform as well as desired in extreme pressure applications, such as cutting, drilling and tapping, and may result in equipment damage. Therefore a functional composition which maintains its properties under conditions of extreme pressure offers significant practical advantages over many compositions known in the art.